U.S. patent number 5,017,175 [Application Number 07/519,720] was granted by the patent office on 1991-05-21 for brake-sizing devices for food stuffing apparatus and methods of use.
This patent grant is currently assigned to Teepak, Inc.. Invention is credited to Galen J. Klusmire.
United States Patent |
5,017,175 |
Klusmire |
May 21, 1991 |
Brake-sizing devices for food stuffing apparatus and methods of
use
Abstract
A highly versatile, resilient and durable food casing sizing
device for regulating the release of unfilled casing from a
stuffing horn is specially useful in filling casings having string
tied end-closures. The sizing ring provides a high degree of
product dimensional uniformity and density. The sizing device which
is flexible can also be used for stuffing delicate thin walled
casings, such as unreinforced thermoplastic types and collagen
casings without damage. The sizing devices are especially useful in
relation to the production of smaller code products stuffed in
plastic or plastic coated casings.
Inventors: |
Klusmire; Galen J. (Carmel,
CA) |
Assignee: |
Teepak, Inc. (Westchester,
IL)
|
Family
ID: |
24069489 |
Appl.
No.: |
07/519,720 |
Filed: |
May 7, 1990 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
312991 |
Feb 17, 1989 |
4932103 |
|
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Current U.S.
Class: |
452/38 |
Current CPC
Class: |
A22C
11/0263 (20130101) |
Current International
Class: |
A22C
11/00 (20060101); A22C 11/02 (20060101); A22C
021/00 () |
Field of
Search: |
;452/38,37 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Little; Willis
Attorney, Agent or Firm: Dunn; Michael L. Sahr; R.
Lawrence
Parent Case Text
RELATED CASE
This is a continuation-in-part of U.S. patent application Ser. No.
07/312,991 filed Feb. 17, 1989 now U.S. Pat. No. 4,932,103.
Claims
What is claimed is:
1. A food casing braking device, which comprises a resilient,
generally sheave-like sizing ring in combination with means for
pressing together said sizing ring, said sizing ring having a
grooved outer rim and an inner rim defining a double tapered bore
for receiving a filling horn of a stuffing apparatus, said sizing
ring being adapted to compress against the food casing and said
filling horn when axially compressed.
2. The food casing braking device of claim 1 wherein the outer rim
of the sizing ring comprises a symmetrically shaped groove.
3. The food casing braking device of claim 1 wherein the outer rim
of the sizing ring comprises an asymmetrically shaped groove.
4. The food casing braking device of claim 2 wherein the outer rim
of the sizing ring comprises a substantially concave-shaped
groove.
5. The food casing braking device of claim 2 wherein the outer rim
of the sizing ring comprises a substantially V-shaped groove.
6. The food casing braking device of claim 3 wherein the outer rim
of the sizing ring comprises an off-center, generally U-shaped
groove.
7. The food casing braking device of claim 1 wherein the inner rim
of the sizing ring includes groove means running generally with the
axial bore.
8. The food casing braking device of claim 1 wherein said sizing
ring comprises first and second end plates and said means for
pressing together said sizing ring comprises first and second
compressing means for engaging opposite sides of said end
plates.
9. The food casing braking device of claim 8 wherein the outer rim
of said sizing ring comprises a symmetrically-shaped groove.
10. The food casing braking device of claim 8 wherein the outer rim
of said sizing ring comprises an asymmetrically-shaped groove.
11. The food casing braking device of claim 8 wherein said first
compressing means comprises means for housing said sizing ring and
said second compressing means comprises a pressure plate for
pressing together said sizing ring in said housing means.
12. The food casing braking device of claim 8 including means for
holding the first and second compressing means towards one another
for compressing segments of the sizing ring together with greater
force than other segments to impart an elliptical configuration to
the sizing ring axial bore and for forming at least one gap between
said inner rim and filling horn.
13. The food casing braking device of claim 8 including means for
holding the first and second compressing means towards one another
for expanding the sizing ring inner rim inwardly to engage casing
on the filling horn circumferentially.
14. The method for filling a tubular food casing which comprises
the steps of:
(a) loading a food casing on a stuffing horn at a filling station,
said casing having interior and exterior walls;
(b) applying a casing brake to said loaded stuffing horn, said
brake comprising a resilient, generally sheave-like sizing ring
having a grooved outer rim and an inner rim defining a double
tapered bore for receiving the loaded stuffing horn, said ring
being axially compressed to circumferentially expand the inner rim
of the sizing ring to engage the exterior wall of said casing,
and
(c) filling the food casing while controlling the release of casing
from the stuffing horn for dimensional uniformity.
15. The method of claim 14 wherein the casing is a member selected
from the group consisting of cellulose, fibrous reinforced
cellulose, thermoplastic, and collagen.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to new and useful devices
and methods of packaging food products, and more specifically, to
an improved tubular casing brake or sizing devices for food
stuffing apparatus.
In the manufacture of sausage products, a tubular food casing, such
as cellulose, is loaded onto the stuffing horn of a filling machine
and stuffed with an emulsion, usually comprised of comminuted meat
together with fillers, seasonings, spices, etc. In the case of
small sausage products, like frankfurters, the filled casings are
twisted, tied, or clipped into suitable links at predetermined
intervals for further processing.
For larger diameter sausage products, like bolognas, salamis, and
the like, the meat emulsion is introduced into larger, heavier
walled fibrous type casings or casings formed from thermoplastic
films, and formed into chubs or lengthy individual sticks. Like the
smaller products, these large diameter sausage products are filled
on stuffing machines comprising a meat pump and a delivery
attachment in the form of a stuffing horn. However, unlike small
diameter products, larger type sausage products, such as bologna,
packaged in large code casings, rely on heavy-duty end-closures in
the form of metal clips or caps which are frequently tied with a
looped string, twine or other equivalent means, all for securely
containing the meat emulsion during the stuffing process and for
hanging or otherwise suspending the product during further
processing, e.g., cooking and smoking, storage and display. U.S.
Pat. No. 4,165,593 is one example of cut lengths of casing closed
at one end with a clip for securing a loop for suspending the
sausage product. The casing, with an end-closure clip and loop
applied to one end, are manufactured in a first operation, and
later, the opened end is fitted onto the horn of a filling machine,
by a meat processor in an independent operation, where it is filled
and then closed at the second end.
In stuffing both small and large diameter casings a sizing or
braking system can be employed for controlling casing expansion to
avoid exceeding casing manufacturers recommended stuffing diameters
while also preventing back "purge" of meat emulsion. This is
achieved with a brake device which applies uniform pressure to the
exterior wall of unfilled casing on a stuffing horn as emulsion
fills the casing interior. The braking device, which may comprise a
ring assembly, engages the casing, restricting its rate of
withdrawal from the horn by applying pressure or drag, generated by
friction, to the casing as it is pulled from the horn by the meat
emulsion being filled or stuffed into that casing. Representative
brake systems are disclosed by U.S. Pat. Nos. 3,748,690
(Niedecker); 3,621,513 (Kupcikevicius); 3,457,588 (Myles et al);
4,438,545 (Kupcikevicius et al) and 4,558,488 (Martinek), to name
but a few.
In most brake/sizing systems compressive force is applied uniformly
and circumferentially (360.degree.) to the outer casing wall
forcing it against the stuffing horn, thus creating friction
between the inner casing wall and the stuffing horn and,
respectively, between the outer casing wall and the brake/sizing
system. The stuffing cycle typically begins with the operator
loading a precut length of casing onto the stuffing horn with the
first end of the casing having an end-closure, e.g. it may be tied
or clipped, and it may have a looped string attached to the
end-closure. The closed, first end of the casing is brought flush
with the outlet end of the horn. The horn and the brake ring
opening are, next, axially aligned. The brake ring assembly is then
forced over the outer wall of the casing, which is on the horn, so
that compressive force is applied to the casing, pushing it against
the horn at a point adjacent to the outlet end of the horn.
Frequently, however, in the process the looped string hanging from
the clipped or capped end-closure or string tied casing becomes
"locked" between the brake ring and casing side wall. Consequently,
unless the string is released before stuffing is initiated, the
casing is unable to peel off the horn and pressure builds up
quickly at the outlet end of the horn causing the casing to
rupture. This means costly down time for cleanup, lost meat
emulsion, lost production and wasted casings.
Accordingly, the present invention contemplates improved
sizing/braking devices for food stuffing apparatus for filling
casings, string tied/looped or otherwise, which can significantly
reduce snagging of the string, where used, and consequent casing
rupture. This translates into economic advantage through higher
production efficiency with reduced potential for down time.
A further important consideration in preparation of both large and
small diameter sausage products is the maintenance of accurate
diametrical and circumferential size control over the entire length
of the sausage stick. It is particularly important that the
diameter of the large sausage products be carefully controlled so
that meat packers are able to cut the sausage into slices of
predetermined thickness and diameter for prepackaging. The
objective is to have a given number of slices weigh precisely a
predetermined amount for each package. For the smaller products, it
is critical that uniform diameters be maintained so that, for
example, when the sausage product is formed into links, each link
weighs the same as all other links, thus enabling the packaging of
those links into standard weight containers. As a result, meat
processors are constantly striving to improve operations that
affect finished package yields. Constant sizing control of green
stick diameter, during stuffing, assures more uniform slice and/or
link weight and minimizes the over and under weight variations of
the packages.
U.S. Pat. Nos. 3,748,690 and 3,872,543 to Niedecker disclose
popular style sizing devices for controlling product diameter.
During filling, controlled release of casing is achieved by a
snubbing element bearing against the outlet end of the stuffing
horn with the casing therebetween. It has been found, however, that
the outlet end of stuffing horns can be fragile and subject to
bending and loss of cylindrical shape unless specially reinforced.
Because of distortion in roundness of horn outlets, snubbing rings,
particularly those which operate by engaging the edge of stuffing
horns, such as disclosed by the Niedecker patents, can fail to
provide accurate product diameter control during filling
operations.
Although snubbing lips of devices like those of Niedecker are
fabricated from essentially resilient materials, they are
nevertheless made relatively rigid and nonflexible due to steel
backing members exerting pressure thereon. Consequently, desired
flexibility and resiliency of such devices may be lost, to a
significant degree, at the point of constriction of casing against
the filling horn, making it difficult for irregular shaped folds in
casing to smoothly negotiate constriction points without producing
deviations in constant pressures and, ultimately, variations in
product diameter. Rigid steel holders for such devices also shorten
the useful life expectancy of their sizing rings due to excess
wear.
Accordingly, the present invention contemplates inter alia improved
flexibility and longer wearing sizing devices which offer a high
degree of dimensional uniformity and caliber control without
dependence on horn roundness and cylindrical shape for optimum size
control during stuffing, and without casing wall thickness
variations interfering with sizing ring performance.
SUMMARY OF THE INVENTION
It is a principal object of the present invention to provide for a
novel food casing braking and sizing device which comprises a
rounded body with an outer grooved rim, generally resembling in
appearance and shape a sheave-like body or sheave wheel, a shape
which is associated with a pulley block for guiding a rope or
cable. The improved sizing ring comprises a resilient, sheave-like
body with a central axis adapted to receive a filling horn of a
stuffing apparatus having casing mounted thereon. The device
frictionally engages the casing against the filling horn, when
axially compressed, causing an inward distortion resulting in a
reduction in inner cross sectional area transverse to the central
axis which results in a pressure restriction being imposed
circumferentially on the longitudinal movement of the casing, thus
braking and rendering uniform the rate of release of the casing
from the horn during the filling cycle. The use of the device
results in void-free filled sausage products of high dimensional
uniformity and consistent density for higher product yield for
presliced or other packaging, notwithstanding distortion or lack of
true roundness at the horn outlet. Because of the flexibility and
resiliency of the sizing ring even at the point of contact with the
casing, even with irregular or heavy folds, and even with
variations in wall thickness, the casing is able to negotiate past
the point of compression of the device against the horn with
relatively constant pressure. This translates into consistent
caliber control for the entire length of the stick and in void-free
constant density stuffing.
It is a further principal object of the present invention to
provide an improved food casing braking device comprising the
resilient, generally sheave-like sizing ring with a grooved outer
rim and an inner rim, in one embodiment, generally defining a
straight axial bore for receiving a filling horn, in combination
with housing means as a first pressure member for the sizing ring
and a pressure plate as the second pressure member for axially
compressing the sizing ring in the housing means. In another
embodiment, the axial bore of the inner rim is double tapered,
having a smaller diameter at a position on the inner rim which
corresponds in position to the smallest diameter of the sheave-like
shape of the outer rim. This latter embodiment is especially useful
with smaller code plastic or plastic coated casings.
It is yet a further object of the invention to provide means for
forcing the pressure members of the sizing ring assembly towards
one another, and holding them in such position, to compress
segment(s) of the ring for imparting various configurations to the
sizing ring bore. For example, by axially compressing segments of
the sizing ring, an elliptical cross sectional configuration,
transverse to the axis, can be imparted to the sizing ring bore
forming at least one gap between the sizing ring inner rim and the
filling horn. This gap permits a looped string or other suspending
means, affixed to one end of a casing from being locked between the
inner rim of the casing brake and outside wall of the casing and
stuffing horn. The sizing ring assembly concurrently restricts
release of casing by imposing compressive force at other points
along the inner rim for continuous and accurate size control. This
significantly reduces the occurrence of casing rupture from jammed
loop string, thus curtailing down time and lost production and
resulting in an important economic advantage over previous efforts
in this field.
It is yet another object of the invention to provide a sizing
device which functions to provide an even and constant feed of
smooth surfaced casing from the horn while maintaining constant
size and density and without friction-loss slippage or
"skipping".
It is also an object of the invention to provide for an improved
method for filling tubular food casing by the steps which
comprise:
(a) loading a precut food casing onto a stuffing horn, wherein the
casing has first and second ends, interior and exterior walls and
an end-closure at the first end with means for suspending the
casing when filled, affixed to the first end;
(b) applying a casing brake to the casing loaded on the stuffing
horn, the brake comprising a resilient, generally sheave-like
sizing ring having a grooved outer rim and an inner rim defining an
axial bore adapted for receiving the stuffing horn, the ring being
axially compressed to impart an elliptical configuration to the
bore, the ring encircling the exterior wall of the casing while the
means for suspending the filled casing lies between the exterior
wall of the casing and inner rim of the sizing ring;
(c) filling the casing with a foodstuff while simultaneously
controlling the rate of release of casing from the stuffing horn
and releasing the means for suspending the filled casing without
rupturing the casing, and
(d) closing the second end of the filled casing.
It is still a further object of the present invention to provide a
method for filling a tubular food casing which includes the steps
of:
(a) loading a food casing on a stuffing horn at a filling station,
the casing having interior and exterior walls;
(b) applying a casing brake to the loaded stuffing horn, the brake
comprising a resilient, generally sheave-like sizing ring having a
grooved outer rim and an inner rim defining an axial bore, either
straight or tapered, adapted for receiving the loaded stuffing
horn, the sizing ring being axially compressed to circumferentially
decrease the inner rim of the sizing ring, reducing its transverse
cross sectional area, to engage the exterior wall of the casing,
compressing them against the outer surface of the stuffing horn,
and
(c) filling the food casing while controlling the release of casing
from the stuffing horn for dimensional uniformity.
DESCRIPTION OF THE DRAWINGS
For a further understanding of the invention as well as its
characterizing features, reference should now be made to the
following detailed description thereof taken in conjunction with
the accompanying drawings wherein:
FIG. 1 is a partial view of a filled food casing with an
end-closure and a looped string affixed to the end-closure.
FIG. 2 is a cut-away side elevational view of the resilient sizing
ring showing the grooved outer rim and internal bore
configurations.
FIG. 3 is a cut-away side elevational view of an alternative
embodiment of the resilient sizing ring.
FIG. 4 is a cut-away side elevational view of yet a further
embodiment of the resilient sizing ring of the invention with an
asymmetrically shaped outer groove.
FIG. 5 is an axial end view of the sheave-like sizing ring with a
funnel guide and groove in the inner rim for releasing the looped
string which may be lodged between the rim and casing on the
stuffing horn.
FIG. 6 is a partially cut-away side elevational view of the brake
assembly over a stuffing horn around which the assembly is
compressed during the filling cycle.
FIG. 7 is a cut-away plan view of the brake assembly including the
sizing ring mounted in a housing.
FIG. 8 is a full end view of the brake assembly with the sizing
ring in the housing as viewed from the meat pump end of the brake
assembly and sizing ring.
FIGS. 9-11 illustrate a progressive sequence of steps in practicing
methods of the present invention.
FIG. 12 is a cut-away plan view of the brake system employed in
stuffing and clipping shirred casing.
FIGS. 13 and 14 are cut-away views of an embodiment of the casing
brake which is particularly useful with small code and plastic or
plastic coated casing.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is shown a filled sausage product 10
having an outer tubular casing 12 which may be a heavy walled
fibrous reinforced type for larger diameter products. For smaller
diameter products unreinforced nonfibrous type casings may suffice.
Casings fabricated from, for example, collagen and thermoplastic
materials, as well as other thin walled films, are also useful in
practicing methods of the present invention. Before shipping to
food processors for filling, clip 14 may be applied as a closure
member affixed to one end of a precut length of casing, and a
heavy-duty looped string or other equivalent hanger means attached
thereto. Such precut casings, having various means for vertically
suspending a product after filling, are widely known and, as such,
form no part of the invention. Although the filled casing of FIG. 1
is shown with a conventional clip 14 and a heavy looped
string/twine 16, alternative end-closures are contemplated for use
with the brake assemblies and methods described herein. One example
would be a metal end-closure cap and a looped string. Methods
contemplated herein also include cut lengths of casing without
metal clips and caps where, instead, end-closures are formed and
tied off with a looped string alone, i.e., string tied casing, or
where the casing, itself, is tied in a knot.
Casing brake 18, as shown in FIG. 2, is one embodiment readily
adapted for controlling the release of casing from a stuffing horn
of a filling apparatus. Brake 18 and alternative embodiments like
those of FIGS. 3 and 4 provide exceptional caliber control and
product uniformity for presliced type packaging with, for instance,
shirred fibrous casing. But, the brake/sizing ring assemblies are
especially well suited for individual precut lengths of casing like
those of FIG. 1 having looped strings 16, etc., as suspending
means. Heretofore, there was a relatively high level of casing
breakage during filling of string tied casings, etc., because
devices used for sizing control, circumferentially engaging the
unfilled casing against the filling horn, did not provide the
clearance needed for releasing the string lodged alongside the horn
upon actuation of the meat pump. Consequently, with the string
stationarily wedged between the sizing control device and the horn,
unfilled casing was unable to readily peel from the horn and
pressure build up would occur rapidly at the horn outlet, rupturing
the casing. Hence, the sizing device of the present invention not
only provide exceptional caliber control for presliced or other
type products, but substantially reduces the frequency of blow-outs
associated with string tied casings, etc.
The casing sizing/braking device comprises a unitized, preferably
one-piece resilient, sheave-like body 18 with a grooved outer or
peripheral rim 20 between first end plate 22 and second end plate
24. The brake includes a central opening or bore 26 defined by a
cylindrically shaped inner rim 28 for receiving the outlet end of a
filling horn shown by broken lines 30 with sufficient clearance to
also accommodate a food casing as is shown in FIGS. 6 and 7.
Grooved outer rim 20 may have virtually any inwardly indented
sectional configuration, provided that, upon axial compression, end
plates 22 and 24 produce an inwardly directed bias, or distortion,
of cylindrically shaped inner rim 28 sufficient to compressively
engage the unfilled casing against the stuffing horn at the time of
filling. Accordingly, the peripheral outer groove 20 may,
longitudinally along the axis, be either symmetrical or
asymmetrical. An example of a suitably grooved outer rim having a
spaced symmetrical configuration is the generally V-shaped groove
32, as shown in FIG. 2, centrally spaced between first and second
end plates 22 and 24. A further representative example of a grooved
outer rim is inwardly rounded or generally concave-shaped groove
34, as shown in FIG. 3, evenly spaced between first and second end
plates 36 and 38.
In those instances where the cylindrical shape of the outlet end of
a filling horn is distorted, not completely round or off-center,
asymmetrical wedge-shaped groove 40, as shown in FIG. 4, has been
found specially effective in maintaining a high level of
dimensional uniformity of product produced. Groove 40 is positioned
closer to first end plate 42 than second end plate 44. With axial
compression of end plates 42 and 44 towards one another, casing is
compressed against the stuffing horn upstream from the edge of the
outlet end of the horn for more uniform controlled release of
unfilled casing. Accordingly, the braking device provides the added
benefit of enabling continued use of dented or damaged horns, or
horns which, through constant use and handling, have lost their
true cylindrical shape, especially at the outlet end, and as a
result, accurate size control over the entire length of the sausage
product would otherwise be lost.
Optionally, but preferably, the sizing devices shown in FIGS. 2-4
include a beveled corner edge 46, 48, 50 adjacent to the junctions
of first end plates 22, 36 and 42, with inner rims 28, 47 and 49,
respectively. A beveled corner edge is useful in facilitating
insertion of the filling horn, loaded with casing, into the bore of
the sizing ring.
The sizing ring, as shown in FIG. 5, may also have a channel or
groove 52 in inner rim 54 running parallel with the axis of the
ring. Groove 52 is a useful guide or trough for a hanging looped
string especially when a heavier gauge of twine must pass through
the space between the inner rim of the sizing ring and the side
wall of the casing. This readily assures passage of the looped
hanger without rupture of the casing when filling is initiated.
Groove 52 may also have a flared funnel or substantially V-shaped
section 56 on the face of end plate 58. V-shaped section 56 is
wider than groove 52 so it readily engages a hanging loop which is
not fully aligned with groove 52. Hence, V-shaped section 56 is a
useful threading means for releasing sizing device pressure on the
string of, for example, string-tied casing.
The foregoing braking/sizing device sheave-like bodies 18, etc.,
are resilient, and may be fabricated from suitable elastomeric
materials, including natural and synthetic rubbers, SBR, ABR, NBR,
polyester and especially polyurethane elastomers, and other food
grade polymers. In some situations, fluorinated polymers may also
be useful. The braking ring can be sufficiently flexible and
resilient for use even with more delicate thin walled, unreinforced
casings having less mechanical strength, e.g., collagen and
thermoplastic types, without damaging them during the filling
process. This flexibility also provides greater resistance to wear,
far exceeding the useful life expectancy of conventional type
sizing rings. In this regard, the sizing rings have an indentation
hardness of about 75 to about 95 on the Shore A Durometer scale,
and more preferably, an indentation hardness from about 85 to 90.
The flexible characteristics of the brake ring not only enable
absorption (passage) of larger heavier casing folds during filling
while maintaining constant pressure for a more uniform finished
caliber and uniform density, but their resilient properties lessen
the rate of wear to the brake ring itself. With other braking
devices, such as those disclosed by Niedecker, where the brake ring
is backed with a rigid steel support, compression of the snubbing
lips against a horn outlet, especially one having irregularities in
roundness, results in excessive wear to the snubbing lips and a
shortened life span for the device.
Referring to FIG. 6, with axial compression of end plates 60, 62
relative to one another, outer rim 64, aligned with adjacent
compressing means 66 and 68, is biased inwardly. The interior
segment of rim 70, coinciding with the inwardly displaced portion
of the braking device, engages unfilled casing 72 as it is
longitudinally pulled along filling horn 74. This engagement
restricts the rate of removal of casing 72, putting a drag or brake
concentrically and evenly all around its circumference.
Thus, assuming an even flow of meat emulsion, at a uniform pressure
and flow rate, through horn 74, and a consistent and corresponding
drag or brake force on casing 72, the drag or brake force causes
casing 72 to be pulled uniformly taut as it is filled with food
stuff. Thus, the product diameter can be regulated and controlled.
Variations on the pressure applied by inwardly displaced rim 70 on
casing 72 will, within modest limits, correspondingly change the
size of the filled casing 72 given an established and uniform rate
of flow and pressure for the dynamic meat emulsion. Of course, too
much pressure and thus, too much brake or drag can be applied,
causing the casing to burst.
As will be discussed in greater detail below, some or all segments
of the end plates of the device may be axially compressed for
either uniform or asymmetrical applications of circumferential
pressure by inner rim 70 against the outer side wall of casing 72,
as well as to vary the degree of that pressure. However, as
illustrated by FIG. 6, one or more segments of the brake ring need
only be compressed for achieving objectives of this invention,
depending on the particular casing type being used. Casing 72
includes a metal end cap closure 76 and looped string 78 attached
thereto. When only a portion of inner rim 70 is forced inwardly the
circular configuration of the inner rim becomes distorted
sufficiently, releasing pressure enough to, in effect, open a slot
80 for passage of looped string 78 past the sizing device,
unencumbered, so rupture of the casing is avoided during the
filling process.
For regulating product diameter, shape and release of string or
other suspending means affixed to the end of a food casing during
filling, the brake assembly comprises first and second compressing
means 66 and 68. However, the braking assembly preferably comprises
a housing 82 and pressure plate 84 for sizing device 86, as shown
in FIGS. 7 and 8. Housing 82 and, especially, pressure plate 84 is
preferably fabricated from thermoplastic and thermosetting polymers
and plastics, including engineering plastics, such as ABS polymers,
polycarbonate resins, polyamide resins, and acetal resins like
those available under the DuPont trademark Delrin. Fluorinated
polymers may also be useful. In addition, the housing and pressure
plate assembly may also be fabricated from suitable metals, such
as, for example, stainless steel and aluminum. Preferably, the
interior of housing 82 will seat resilient sizing device 86 without
residual slack when in a relaxed state. Pressure plate 84 should
slidably fit in the interior of housing rim 88 (FIG. 7) with
sufficient space 90 remaining for axial compression of the sizing
device 86 before making contact with inner ledge stop 92. Thus, in
one embodiment the housing includes threaded bolts 94 at opposing
segments of the housing assembly which pass through openings in the
pressure plate 84. That is, pressure plate 84 is affixed to housing
82 with means for holding and moving the two components towards one
another, e.g., with threaded bolts 94, washers 96 and threaded hex
nuts 98 as shown by FIGS. 7 and 8 for selectively and adjustably
compressing segments of sizing device 86 together with greater or
equal force than other adjacent segments of the ring not having
such threaded bolts, etc.
The central opening 100 of the housing and pressure plate assembly
is partially filled with inner rim 102 of resilient sizing device
86 Central opening 100 is also of sufficient diameter to receive
filling horn 104 loaded with casing 106 having an end-closure cap
108 and a looped string 110 held along the outer side wall of the
casing and filling horn.
As threaded hex nuts 98 of the casing brake assembly are tightened
against pressure plate 84, resilient sizing device 86 becomes
compressed. However, because the segments of the device in the
region of the bolts and nuts are under greatest compressive forces,
assuming some flex of pressure plate 84, only segments of the inner
rim 102, and not the whole of the inner rim 102, uniformly, are
driven inwardly as shown by arrows 112 and 114 against the casing
106 and the horn 104. Inner rim 102 of resilient sizing device 86
loses its circular configuration and assumes an elliptical-like
shape. As a result, a gap 116 is formed at the bottom region of
inner rim 102, between inner rim 102 and filling horn 104, allowing
looped string 110 to pass (slip through) without resulting in the
tearing or rupturing of the casing 106 when the meat pump (not
shown) is actuated for filling the casing 106.
FIGS. 9-11 provide a sequence of steps for practicing methods of
the invention. Typically, the food stuffing apparatus employed will
have a meat pump of conventional design (not shown), a stuffing
horn 120 which may be axially extendible, and the food casing brake
assembly 122. Brake assembly 122 includes means 124 for pivoting
sizing device 126 downwardly away from the stuffing horn and tie
rods 128 for supporting the sizing device. The sizing device 126
includes the hollow sizing ring 130 having a resilient, sheave-like
body, a first compression ring 132, a second compression ring 134
and screws 136 on each side of the horn for adjusting the force
applied to compression rings 132 and 134 and, thus, to segments of
sizing ring 130 lateral to the central axis.
FIG. 10 illustrates downward displacement of food casing braking
assembly 122 away from horn 120 for loading of a cut length of
string-tied casing 140 onto horn 120. FIG. 11 shows alignment of
brake assembly 122 with horn 120 which is axially extended into the
bore of the sizing ring 130. String tied loop 144 which is folded
against the outer side wall of the casing 140 before filling is
initiated, is enabled to pass through ring 130 without rupturing
the casing, provided that sizing ring 130 is compressed such that
both elliptical configuration of the bore thereof is formed, and
the release of unfilled casing from the stuffing horn is
simultaneously regulated for diametrical size control.
Methods of the present invention have been illustrated thus far
principally in connection with precut lengths of string-tied
casing. However, the invention also contemplates methods of filling
shirred casings, both fibrous and nonfibrous reinforced types,
including thermoplastic types without string-tied end-closures.
This also includes 72 inch long casings--Code 9 (4.65 caliber) for
slicing, as well as smaller codes in the 11/2-21/2" diameter range.
FIG. 12 demonstrates one application of shirred casing in filling
smaller diameter clipped sausages. Sizing ring 150, having a
resilient, sheave-like body, is axially engaged at opposite ends
with compression rings 152 and 154, respectively, which, in turn,
are affixed with connecting screws 155 and 156 for adjusting the
force exerted on sizing ring 150. Compression ring 152 may be a
rigid metallic member which does not warp or flex when forced
against the sizing ring by the tightening of connecting screws 155
and 156. The objective of the embodiment of FIG. 12 is to apply
uniform axial compressive pressure to sizing ring 150 at all
segments of the ring's peripheral edge so that the inner rim 157 of
the sizing ring uniformly circumferentially engages (360.degree.)
the casing 146 on the stuffing horn 147, applying uniform and
equalized pressure at all points around that circumference, thus
resulting in the preparation of straight, dimensionally uniform
sausages 162. The leading and trailing ends of each sausage may be,
for example, tied off at clipper 166 with metals clips 160.
In producing smaller code sausage products, having diameters in the
range of about 11/2" to about 21/2", in many cases plastic coated
fibrous casings and, simply, straight plastic casings are used. The
smaller codes require more force to expand them, based on the basic
principles of hydraulics. Because more force is required, the
braking/sizing device is required to exert increased pressure on
the casings in comparison to that which is required for the
production of larger code products. The plastic materials, either
in the form of casing coatings or as casing materials, per se, tend
to exhibit higher strengths and are less prone to bursting under
increased filling pressures. That is to say, such casings tend to
expand to a greater degree under pressure before exceeding their
strength capacities in comparison to casings made from other
materials.
Because plastics tend to have a higher degree of surface lubricity
than other types of casing materials, it is more difficult to apply
effective braking to such casings, whether plastic coated or
straight plastic, in comparison to other materials. The compressive
force applied to the outer casing wall must be increased to
overcome the lubricity and to apply sufficient drag or braking
force to ensure uniform sizing and density of the sausage product
being stuffed. Yet the compressive force cannot be increased to the
point where it causes the casing to burst.
As explained previously, casings which are packed onto the horn are
not necessarily uniform; there are variations in the wall thickness
of the casings and some variations in the diameter of the casing.
In addition, the casing which is mounted onto the horn is done so
in accordion fashion with the accordion pleats being variable and
the bends forming those pleats being variable. In other words,
within the parameters of the casing size, the accordion pleating of
the casing, as mounted on the horn, is random, thus the force to
pull it out of the accordion pleated set, before it even reaches
the braking/sizing device, can vary somewhat both longitudinally
and transversely from point to point around the circumference of
the casing.
As is well known, there is a significantly greater amount of force
required to overcome the effects of static fraction than that which
is required to keep something moving in a dynamic friction
situation. Because of the relatively high degree of compressive
force required to be imposed onto plastic casing or plastic coated
casing by the brake/sizing device, when producing smaller code
(11/2"-21/2" diameter) sausage products, a greater degree of force
is required to get the casing moving between the brake/sizing
device and the horn. This is not a problem in start-up as there
tends to be a modest impact imposed against the closed end of the
casing by the meat emulsion as it is pumped through the horn. The
problem occurs when, due to size and thickness variations and the
random nature of the accordion pleats, there is a variation,
amounting to discrete points of hesitation, of the movement of the
casing as it enters the brake/sizing device. Due to the difference
in force required vis-a-vis that required for overcoming static
friction in comparison to that required for overcoming dynamic
friction, the filling case, following the exit from the
brake/sizing device tends to exhibit slip or "skip" hesitation in
its movement, with variations in speed of exit and in amount of
stretch and with momentary stop-start jerking movements. As might
be expected, this causes havoc with the uniformity of product size
and density.
An embodiment of the present invention overcomes this problem.
Referring to FIG. 13, there is shown a modified casing brake 170
which is identical, in all respects, to casing brake -8 shown in
FIG. 2, except there is a double taper to the bore 172 in the form
of a "V". As seen in FIG. 13, casing brake 170 is in a state where
no compressive pressure is being exerted on it, axial or otherwise.
The tip 174 of the "V" is spaced apart from the horn 176 as shown
in FIG. 13.
The same casing brake 170 is shown in FIG. 14, but this time with
the requisite axial compressive force applied by any one of the
means described previously in relation to the illustrations of
FIGS. 6-8 and FIG. 12. The tip 174 of the "V" shown in FIG. 13 is
transformed into contact area 178 in FIG. 14 by compression against
horn 176 with the casing (not shown in FIGS. 13 and 14)
therebetween. As will be noted in comparing FIG. 14 to, for
example, FIGS. 6 and 7, the area of contact between the casing
brake and the horn, with the casing therebetween, is substantially
less for FIG. 14.
Tests have shown that the use of casing brake 170 with small code
casing in the range of about 11/2" diameter to about 21/2"
diameter, where the casing material is plastic or plastic coated,
substantially eliminates the slip or "skip" phenomena otherwise
experienced, thus restoring size and density uniformity to the
sausage products being produced.
Although the invention has been described in considerable detail
with respect to the preferred embodiments thereof, it will be
apparent that the invention is capable of numerous modifications
and variations to those skilled in the art without departing from
the spirit and scope of the invention as defined in the appended
claims.
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